Cutting-tool for sound-recording machines.



PATBNTED JAN. 3,1905, E. R. JOHNSON. CUTTING TOOL FOR sown 330mm momma- APPLICATION FILED mm. 1 6,

N6. 778,975. Patented Januar 's, 1905'.

UNITED STATES PATENT OFFICE? ELDRIDGE R. OHNSON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO VICTOR TALKING MACHINE COMPANY, A CORPORATION OF NEW JERSEY.

CUTTl NG- TOOL FOR SOUND-RECORDING MACHINES.

SPECIFICATION forming part of Letters Patent No. 778,975, dated J'anuaryB, 1905. Application filed August 16, 1898. Serial No. 638,695-

To whom it y con/061'"! applicable to other constructions of recording- Be it known that I, ELDRIDGE R. JOHNSON, machines than that hereinbefore more particu- 5 a citizen of the United States, and a. resident larly referred to.

of the city of Philadelphia, State of Pennsyl- In the accompanying drawings, which illus- Vania, have invented certain new and useful trate my invention and the application thereof Improvements inCutting-Tools for Sound-Reon an enlarged scale, Figure 1 is a partiallycording Machines, of which the following is a sectional view representing my improved tool 5 5 full, clear, and exact descri 'it-ion, referencebein position attached to the stylus-bar of the ing had to the accompanyingdrawings, formstylus or tool of a sound-recording machine I0 ing part of this specification. in the process of cutting a recording-groove My invention has relation to tools for cutupon a plate of wax or other semiplastic matingrecords in sound-recording machines; and terial. Fig. 2 is a perspective view. of the 60 it consists in the construction hereinafter decutting-tool detached. Fig. 3 is an erllarged scribed and claimed. I cross-sectionalviewpfa rccording-plate,sliow- 5 In producing records upon sound-recording ing the walls of the groove as'formed by my machines for use upon talking-machines, such improved cutting-tool. Fig. at is a similar as the gramophones, where the sound-waves view illustrating the face of the cutting-tool 65 are recorded in the sides of the groove in the in position in the groove. Fig. 5 is a plan record instead of in the base, as in the type View of a recording-plate of circular form of machine of which the phonograph is an with the recording-grooves provided in the illustration, it is essential in order to produce face thereof. Fig. 6 illustrates to an exaga clear record that the material be cleanly and gerated extent a section of a record-groove 7 neatly cutfrom the groove in the process of with the lines of the sound-waves in the sides recording, so that sharp well-defined lines will thereof.

5 be formed in the wallsof the groove. I-have A re resents the cutting-tool, secured upon discovered that in order t'o produce the best the on of the stylus-bar I through the meresults these side walls of the groove must he dium of the T-shaped section '1 the upper 75 at a slight angle to the face of the plate or end of the tool being secured in the orifice record and the groove must ,be widest at the I) of the section B through the medium of the 3 mouth. \Vhere the walls are perpendicular thumb-screw 7' v or slightly wider at a point below the mouth The tool A is necessarily for the purposes of the groove, inferior results are produced, of illustration very much enlarged in the and the record is by no means as durable. drawings. as in practice the cutting-face ot' the The object of my present invention is to instrument is preferably reduced to two and provide a cutting-tool for cutting grooves in. a half one-thousandths of an inch in its largest wax or other suitable material for recording diameter, and the greatest care must be obsoundwaves of the construction above reserved inthe preparation of the cutting-face. ferred to, my aim being to provide a tool of Thetool A is preferably conical, being at the microscopic proportions peculiarly formed upper end of a suitable diameter to be evenly 4 with a flat face of substantially oval form, the held in the stylus-section B through the me edges of the oval beingcutting edges to cleanly dium of the thumb-screw Ii and gradually recut the material from the resultant groove, duced to or near the cutting-face a to a diam- 9 leaving sharp smooth well-defined edges, the eter ofabout two and a half one-thousandths fiat face being preferably obliquely disposed of an inch, The face a is cut and formed,

to the axial line of the tool, so that when in preferably, at an angle to the axial line of the position in operation to present a cutting-face tool A, so that when the tool is in position in substantially perpendicular. operation at about the angle illustrated in It is clear that my invention may also be I Fig. 1 the cutting-face will assume an angle 5 ellipse.

Letters Patent No. 778,975.

substantially .vertical or at about a right angle to the face of the plate upon which the record is being produced. The edges a of the cutting-face form, preferably, substantially an These edges a are carefully'formed to present acutting edge, so that as the moving record is traveled against the face a of the tool A when held in position, as indicated in Fig. 1, the knife-edges ct will cleanly cut the material from the record, forming a cleancut' groove, with the undulation or sound waves produced by the vibration of the stylus formed in the record, as shown in Fig. 5 and illustrated in cross-section in Fig. 3. The shape of the face a is preferablythe resultant of a cone intersected by a plane at an angle to its axis.

In operation any suitable means are pro vided for preventing the cutting-tool from entering the wax beyond the line, as approximately indicated in Figs 1, 3, and 4. The

tool should enter to a line slightly below the greatest diameter of the face a, as indicated in Fig. 4. It is understood that in reproducing the record thus formed may be used for reproducing purposes directly, or a more dulcns -in [SEAL] Correct therein that the same may conform to the record of thecase in the Patent Ofiice.

Signed and sealed this 17th day of JanuaryQ-i. D., 1905.

rable and indestructible record may be reproduced by various processes from the original record.' This feature, however, forms no part;

In a soundrrecording machine, a cuttingtool comprising aneedle having a conical end portion" terminating in a! surface having the form of a conic section taken at an angle to the axis of the needle, the surface of the conic section being at such an angle to the axis that when the needle is in the correct relation to a recording-surface, the former will be substantially perpendicular to said recording-surface and whereby chips of material will be deflected from the groove and the free cutting side edges of the conic section will havefree and -unt'ram meled action, substantially as described.

In witness whereof I have hereunto setgny hand this 12th day of August. A. 1).1898. ELDRIDGE R. JOHNSON.

Witnesses:

BENJ. F. PERKINS, HORACE PETTIT.

It is hereby certified that in Letters Patent No. 778,975, granted January 3, 1905, upon the application. of Eldridge R. Johnson, of Philadelphia,

improvement in Cutting-Tools for Sound-Recording Machines,

Pennsylvania, for an errors appear in the printed specification requiring correction, as follows: On page 1, line 55, after the word improved, the words stylus or should be inserted; same page, line 56, the word ctions- F. I. ALLEN,

Commissioner of Patents.

the at the end of the line and the words stylus or tool of, in line 57, should be stricken out; and that the said Letters Patent should be read with these corre 

